Tempering channels being designed as cooling channels for confectioneries are known from German Patent Application No. DE 196 07 055 A1 corresponding to European Patent No. EP 0 797 923 B1 as well as from European Patent No. EP 1 046 343 B1 corresponding to U.S. Pat. No. 6,263,681 B1. The known tempering channel includes a tempering tunnel in one of its sections. In case the tempering tunnel only extends in a middle portion of the tempering channel, the tempering channel may also include an entrance zone and an exit zone in which the tempering tunnel is not located. An endless and driven conveyor belt is moved through the tempering tunnel. The confectioneries to be tempered are located on the conveyor belt, and they are guided through the tempering tunnel along the length of the tempering channel. The tempering tunnel includes a tempering apparatus with which the confectioneries placed on the conveyor belt are tempered, meaning they are temporarily either cooled or heated. The tempering apparatus may also be designed to have different effects in different zones. In all cases, the tempering apparatus serves to influence the temperature of the confectioneries. Depending on the design of the tempering channel and of the tempering tunnel, respectively, the lower part of the conveyor belt is either moved back below of the tempering tunnel inside of the tempering tunnel or outside of the tempering tunnel. The known tempering channels, especially with respect to their cooling channels, are designed in a way that the tempering apparatus in the tempering tunnel acts upon the confectioneries. For example, the confectionery products are cooled or otherwise subjected to a temperature profile along their way along the length of the tempering tunnel. In many cases, this is sufficient to attain confectioneries in accordance with the desired result.
Other cooling channels in which the cooling apparatus being located in the cooling tunnel is precisely controlled with respect to temperature are also known in the prior art. The control is realized in the sense of optimizing crystallization of components of the confectioneries. Crystallization, for example of chocolate mass, already begins in the tempering machine, and it is then fully or at least widely completed in the cooling tunnel.
Chocolate bar casting apparatuses including a tempering channel and a conveyor belt are also known in the prior art. The conveyor belt is made of steel and the casting molds being made of plastic are supported on the conveyor belt. The chocolate bars are formed in the casting molds. The end of the upper part of the conveyor belt downstream of the tempering tunnel is cooled by spraying cooling water onto from below. Such cooling exclusively serves to directly cool the chocolate bars to simplify detachment of the chocolate bars from the casting molds downstream of the tempering tunnel.
Tempering channels being designed as baking ovens for confectioneries are also known in the prior art. A cooling apparatus is arranged at the end of the tempering channel. The cooling apparatus serves to effectively cool the products.
Another cooling channel being operated in an energy saving way is known in the prior art. The lower part of the conveyor belt is moved through the cooling tunnel to attain an undefined low temperature of the conveyor belt during its entire rotation. However, the undefined low temperature is disadvantageous for different confectioneries, and it is not an optimal temperature as it would make sense for continuing crystallization of a chocolate mass of a product, for example.
A cooling tunnel for confectioneries and long-life bakery products is known from German Patent Application No. DE 40 40 429 A1. The cooling tunnel includes a conveyor belt the lower part of which is moved back through the cooling tunnel. Each section of the cooling channel includes an air cooler. The cooled air is guided over the confectioneries placed on the upper part of the conveyor belt, over the bottom sheet and over the lower part of the conveyor belt. It is desired to keep the temperature of the conveyor belt at the transfer location between the coating machine and the cooling channel at a substantially lower value compared to the value which would be attained when moving back the lower part of the conveyor belt outside of the cooling tunnel. Due to the fact that the cooling channel only includes one cooling apparatus, namely the air cooler, and the air cooler primarily serves to cool the confectioneries, one randomly attains a substantially lower value of the temperature of the lower part of the conveyor belt during cooling. This temperature of the lower part of the conveyor belt changes in different ways depending on the length of the entrance zone. This temperature is disadvantageous for different confectioneries, and it is not an optimal temperature at the transfer location, as it would make sense for continuation of crystallization of a chocolate mass located on a product exiting from a coating machine, for example.